title: Proteomic identification of keratin alterations with enhanced proliferation of oral carcinoma cells by loss of mucosa-associated lymphoid tissue 1 expression.
abstract: Progression of oral carcinomas associates with aberrant activation and inactivation of molecules that work in established or unknown pathways. Although mucosa‑associated lymphoid tissue 1 (MALT1) expressed in normal oral epithelium is inactivated in the aggressive subset of carcinomas with worse prognosis, phenotypic changes of carcinoma cells upon the loss of expression is unknown. We performed a proteomic analysis to identify MALT1‑regulated proteins in oral carcinoma cells. Four different keratins were included in the ten most abundantly changed proteins. K8/18 were upregulated in MALT1 stably‑expressing carcinoma cells and K5/14 in MALT1‑marginal control cells. K8/18 upregulation and K5/14 downregulation were MALT1 dose‑dependent and observed in a series of oral carcinoma cells. MALT1 suppressed cell proliferation (0.52-fold, P<0.01) and its dominant-negative form stimulated it (1.33-fold, P<0.01). The decreased proliferation associated with reduction of cyclin D1, which was recovered by the short interfering RNA against MALT1. Taken together, loss of MALT1 expression alters keratin expression and enhances proliferation of carcinoma cells, and may progress oral carcinomas into the advanced state.
authors.affiliation: Division of Oral and Maxillofacial Surgery 2, Department of Diagnostic and Therapeutic Sciences, School of Dentistry, Meikai University, Saitama, Japan.
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Kawamoto
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Ohyama
authors.forename: Tadashige
authors.initials: T
authors.lastname: Chiba
authors.forename: Hisao
authors.initials: H
authors.lastname: Yagishita
authors.forename: Hideaki
authors.initials: H
authors.lastname: Sakashita
authors.forename: Kazushi
authors.initials: K
authors.lastname: Imai
mesh_terms: D002277:Carcinoma / Q000235:genetics* / Q000473:pathology; D020169:Caspases / Q000096:biosynthesis / Q000235:genetics*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D019938:Cyclin D1 / Q000096:biosynthesis; D004848:Epithelium / Q000378:metabolism / Q000473:pathology; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007633:Keratins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D009062:Mouth Neoplasms / Q000235:genetics* / Q000473:pathology; D000074884:Mucosa-Associated Lymphoid Tissue Lymphoma Translocation 1 Protein; D009092:Mucous Membrane / Q000378:metabolism / Q000473:pathology; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000235:genetics*; D040901:Proteomics / Q000379:methods; D015854:Up-Regulation
chemical_list: D009363:Neoplasm Proteins; D019938:Cyclin D1; D007633:Keratins; D020169:Caspases; C400109:MALT1 protein, human; D000074884:Mucosa-Associated Lymphoid Tissue Lymphoma Translocation 1 Protein